The new semester in Sharif university begins.This term
Dr. Reza Mansouri,/
http://en.wikipedia.org/wiki/Reza_Mansouri /one of the prominent scientists of Iran teach General relativity and gravitation. Dr. Mansouri which recieved his Ph.D. in Austria in begining of 1970s is the first one who taught general relativity in Iran.
In first session he take a look on history of general relativity and cosmology.
The below is a more complete list of the happenings since the foundation of Special relativity in 1905.
1905 - Albert Einstein , special relativity
1907 - Albert Einstein introduces the
principle of equivalence of gravitation and inertia
1915 - Albert Einstein - general relativity.
1915 - Karl Schwarzschild -
Schwarzschild metric ,first solution to the Einstein field
1916 - Albert Einstein - field equations of general relativity admit wavelike solutions
1917 - Willem de Sitter derives an isotropic static cosmology with a cosmological constant, as well as an empty expanding cosmology with a cosmological constant, termed a
de Sitter universe.
1918 - J. Lense and Hans Thirring find the gravitomagnetic precession of
gyroscopes GR
1919 - Arthur Eddington -solar
eclipse expedition- detection gravitational deflection of light
1921 - Theodor Kaluza 5-dimensional version of GR equations unifies gravitation and EM
1922 - Alexander Friedmann finds a solution to the Einstein field equations which suggests a general expansion of space
1927 - Georges LemaĆ®tre discusses the creation event of an expanding universe governed by the Einstein field equations.
1929 - Edwin Hubble demonstrates the linear redshift-distance relation and thus shows the expansion of the universe
1933 - Edward Milne names and formalizes the cosmological principle 1934 - Georges LemaĆ®tre interprets the cosmological constant as due to a vacuum energy with an unusual perfect fluid equation of state
1937 -
Fritz Zwicky states that galaxies could act as gravitational lenses
1937 - Albert Einstein, Leopold Infeld, and Banesh Hoffmann -geodesic equations of GR can be deduced from its field equations
1938 - Paul Dirac suggests the large numbers hypothesis, that the gravitational constant may be small because it is decreasing slowly with time.
1948 - Hermann Bondi, Thomas Gold, and Fred Hoyle propose steady state cosmologies based on the perfect cosmological principle.
1948 - George Gamow predicts the existence of the cosmic microwave background radiation by considering the behavior of primordial radiation in an expanding universe
1950 - Fred Hoyle derisively coins the term "Big Bang".
1957 - John Wheeler discusses the breakdown of classical general relativity near singularities and the need for quantum gravity.
1960 - Robert Pound and Glen Rebka test the gravitational redshift predicted by EP the approximately 1%
1961 - Robert Dicke argues that carbon-based life can only arise when the gravitational force is small, because this is when burning stars exist; first use of the weak anthropic principle
1962 - Robert Dicke, Peter Roll, and R. Krotkov use a torsion fiber balance to test the weak equivalence principle to 2 parts in 100 billion
1964 - Irwin Shapiro predicts a gravitational time delay of radiation travel as a test GR
1965 - Joseph Weber puts the first Weber bar gravitational wave detector into operation
1965 - Martin Rees and Dennis Sciama analyze quasar source count data and discover that the quasar density increases with redshift.
1965 - Arno Penzias and Robert Wilson, astronomers at Bell Labs discover the 2.7 K microwave background radiation, which earns them the 1978 Nobel Prize in Physics. Robert Dicke, James Peebles, Peter Roll and David Todd Wilkinson interpret it as relic from the big bang.
1966 - Stephen Hawking and George Ellis show that any plausible general relativistic cosmology is singular
1966 - James Peebles shows that the hot Big Bang predicts the correct helium abundance
1967 - Andrei Sakharov presents the requirements for baryogenesis, a baryon-antibaryon asymmetry in the universe
1968 - Irwin Shapiro presents the first detection of the Shapiro delay
1968 - Kenneth Nordtvedt studies a possible violation of the weak equivalence principle for self-gravitating bodies and proposes a new test of the weak equivalence principle based on observing the relative motion of the Earth and Moon in the Sun's gravitational field.
1969 - Charles Misner formally presents the Big Bang horizon problem 1969 - Robert Dicke formally presents the Big Bang flatness problem.
1974 - Robert Wagoner, William Fowler, and Fred Hoyle show that the hot Big Bang predicts the correct deuterium and lithium abundances
1976 - Robert Vessot and Martin Levine use a hydrogen maser clock on a Scout D rocket to test the gravitational redshift predicted by the equivalence principle to approximately 0.007%
1976 - Gravity Probe A experiment confirmed slowing the flow of time caused by gravity matching the predicted effects to an accuracy of about 70 parts per million.
1979 - Dennis Walsh, Robert Carswell, and Ray Weymann discover the gravitationally lensed quasar Q0957+561
1981 - Viacheslav Mukhanov and G. Chibisov propose that quantum fluctuations could lead to large scale structure in an inflationary universe 1981 - Alan Guth proposes the inflationary Big Bang universe as a possible solution to the horizon and flatness problems
1982 - Joseph Taylor and Joel Weisberg show that the rate of energy loss from the binary pulsar PSR B1913+16 agrees with that predicted by the general relativistic quadrupole formula to within 5%
1990 - Preliminary results from NASA's COBE mission confirm the cosmic microwave background radiation is an isotropic blackbody to an astonishing one part in 105 precision, thus eliminating the possibility of an integrated starlight model proposed for the background by steady state enthusiasts.
1990s - Ground based cosmic microwave background experiments measure the first peak, determine that the universe is geometrically flat
1998 - Controversial evidence for the fine structure constant varying over the lifetime of the universe is first published.
1998 - Adam Riess, Saul Perlmutter and others discover the cosmic acceleration in observations of Type Ia supernovae providing the first evidence for a non-zero cosmological constant.
1999 - Measurements of the cosmic microwave background radiation (most notably by the BOOMERanG experiment see Mauskopf et al., 1999, Melchiorri et al., 1999, de Bernardis et al. 2000) provide evidence for oscillations (peaks) in the anisotropy angular spectrum as expected in the standard model of cosmological structure formation. These results indicates that the geometry of the universe is flat. Together with large scale structure data, this provides complementary evidence for a non-zero cosmological constant.
2002 - The Cosmic Background Imager (CBI) in Chile obtained images of the cosmic microwave background radiation with the highest angular resolution of 4 arcmin. It also obtained the anisotropy spectrum at high-resolution not covered before up to l ~ 3000. It found a slight excess in power at high-resolution (l > 2500) not yet completely explained, the so-called "CBI-excess".
2003 - NASA's WMAP obtained full-sky detailed pictures of the cosmic microwave background radiation. The image can be interpreted to indicate that the universe is 13.7 billion years old (within one percent error) and confirm that the Lambda-CDM model and the inflationary theory are correct. 2003 - The Sloan Great Wall is discovered.
2004 - The Cosmic Background Imager first obtained the E-mode polarization spectrum of the cosmic microwave background radiation.
2006 - The long-awaited three-year WMAP results are released, confirming previous analysis, correcting several points, and including polarization data.
2007 - End of Gravity Probe B experiment.
No comments:
Post a Comment